Respiratory Syncytial Virus (RSV) is a leading cause of serious respiratory disease in young children and the elderly worldwide and there is no vaccine available against this pathogen. Human respiratory syncytial virus (HRSV) is the most common etiological agent of acute lower respiratory tract disease in infants and can cause repeated infections throughout life. It is classified within the genus pneumovirus of the family paramyxoviridae. Like other members of the family, HRSV has two major surface glycoproteins (G and F) that play important roles in the initial stages of the infectious cycle. The G protein mediates attachment of the virus to cell surface receptors, while the F protein promotes fusion of the viral and cellular membranes, allowing entry of the virus ribonucleoprotein into the cell cytoplasm.
Respiratory syncytial virus (RSV) infection commonly results in bronchiolitis and is the leading cause for infant hospitalization in the developed countries. In addition, RSV is increasingly being described as a major pathogen in the elderly, transplant patients, and chronic obstructive pulmonary disease (COPD) patients (Hacking and Hull, 2002). The development of a safe and immunogenic vaccine to address the infant and elderly population presents a unique opportunity.
Previous methods of viral inactivation for vaccine formulation, such as formaldehyde, resulted in enhanced pulmonary disease and mortality. Extensive research into the development of viral vaccines to address RSV has met with limited success. Some of the major challenges for RSV vaccine development includes, early age of infection, evasion of innate immunity, failure of natural infection to induce immunity that prevent infection and the demonstration of vaccine-enhance illness coupled with problems associated with vaccine stability, purity, reproducibility and potency (Graham, 2011; Swanson and Settembre, 2011).
Approaches have included inactivation or viruses with formalin and the demonstration of vaccine-induced enhancement of diseases when infected with RSV. The observation that formalin inactivated vaccines have shown diseases-enhancement, included showing the skewed immune response that is important to prevent enhancement are essential for a protective immune response and having F protein its native state to maintain conformational epitopes is essential for the generation of neutralizing antibodies (Krujigen, 2011; Swanson 2011; McLellan et al., 2011). The demonstration that formalin-inactivated RSV vaccine diseases enhancement is not attributable to G protein and that G protein antibodies can reduce viral titers and actually protects against diseases enhancement suggests that G protein can be incorporated into a vaccine candidate (Radu et al, 2010; Haynes et al, 2009; Johnson et al, 2004). The use of live attenuated vaccines have met with limited success, as the vaccines have been shown to be minimally immunogenic (Gomez et al 2009). The utilization of a recombinant viral expressed F and G proteins vaccine showed reduced immunogenicity associated with low level of antigen expression, transient level of expression, cellular specificity and the demonstration that the purified F protein can be structurally immature and not the appropriate version for eliciting neutralizing antibodies (Singh and Dennis, 2007; Kim et al, 2010). With the use of subunit vaccine, having an optimal level of F protein is critical for inducing the appropriate immune response, as the subunit vaccines have been hindered by the inefficient and inappropriate expression of F and G proteins (Nallet et al., 2009; Huang and Lawlor 2010). The observation that subunit vaccine containing F protein, even with adjuvant is not completely protective and optimal (Langley et al., 2009), suggests that F protein presentation within its native state in the virion is essential for usage as a vaccine.
Prior teachings related to nanoemulsions are described in U.S. Pat. No. 6,015,832, which is directed to methods of inactivating Gram-positive bacteria, a bacterial spore, or Gram-negative bacteria. The methods comprise contacting the Gram-positive bacteria, bacterial spore, or Gram-negative bacteria with a bacteria-inactivating (or bacterial-spore inactivating) emulsion. U.S. Pat. No. 6,506,803 is directed to methods of killing or neutralizing microbial agents (e.g., bacterial, virus, spores, fungus, on or in humans using an emulsion. U.S. Pat. No. 6,559,189 is directed to methods for decontaminating a sample (human, animal, food, medical device, etc.) comprising contacting the sample with a nanoemulsion. The nanoemulsion, when contacted with bacteria, virus, fungi, protozoa or spores, kills or disables the pathogens. The antimicrobial nanoemulsion comprises a quaternary ammonium compound, one of ethanol/glycerol/PEG, and a surfactant. U.S. Pat. No. 6,635,676 is directed to two different compositions and methods of decontaminating samples by treating a sample with either of the compositions. Composition 1 comprises an emulsion that is antimicrobial against bacteria, virus, fungi, protozoa, and spores. The emulsions comprise an oil and a quaternary ammonium compound. U.S. Pat. No. 7,314,624 is directed to methods of inducing an immune response to an immunogen comprising treating a subject via a mucosal surface with a combination of an immunogen and a nanoemulsion. The nanoemulsion comprises oil, ethanol, a surfactant, a quaternary ammonium compound, and distilled water. US-2005-0208083 and US-2006-0251684 are directed to nanoemulsions having droplets with preferred sizes. US-2007-0054834 is directed to compositions comprising quaternary ammonium halides and methods of using the same to treat infectious conditions. The quaternary ammonium compound may be provided as part of an emulsion. US-2007-0036831 and US 2011-0200657 are directed to nanoemulsions comprising an anti-inflammatory agent. Other publications that describe nanoemulsions include U.S. Pat. No. 8,226,965 for “Methods of treating fungal, yeast and mold infections;” US 2009-0269394 for “Methods and compositions for treating onychomycosis;” US 2010-0075914 for “Methods for treating herpes virus infections;” US 2010-0092526 for “Nanoemulsion therapeutic compositions and methods of using the same;” US 2010-0226983 for “Compositions for treatment and prevention of acne, methods of making the compositions, and methods of use thereof;” US 2012-0171249 for “Compositions for inactivating pathogenic microorganisms, methods of making the compositions, and methods of use thereof;” and US 2012-0064136 for “Anti-aging and wrinkle treatment methods using nanoemulsion compositions.” However, none of these references teach the methods, compositions and kits of the present invention.
In particular, U.S. Pat. No. 7,314,624 describes nanoemulsion vaccines. However, this reference does not teach the ability to induce a protective immune response to RSV using the immunogen of the invention.
Prior art directed to vaccines includes, for example, U.S. Pat. No. 7,731,967 for “Composition for inducing immune response” (Novartis), which describes an antigen/adjuvant complex comprising at least two adjuvants. U.S. Pat. No. 7,357,936 for “Adjuvant systems and vaccines” (GSK) describes a combination of adjuvant and antigens. U.S. Pat. No. 7,323,182 for “Oil in water emulsion containing saponins” (GSK) describes a vaccine composition with an oil/water formulation. U.S. Pat. No. 6,867,000 for “Method of enhancing immune response to herpes” (Wyeth) describes a combination of viral antigens and cytokines (IL12). U.S. Pat. Nos. 6,623,739, 6,372,227, and 6,146,632, all for “Vaccines” (GSK), are directed to an immunogenic composition comprising an antigen and/or antigen composition and an adjuvant consisting of a metabolizable oil and alpha tocopherol in the form of an oil in water emulsion. U.S. Pat. No. 6,451,325 for “Adjuvant formulation comprising a submicron oil droplet emulsion” (Chiron) is directed to an adjuvant composition comprising a metabolizable oil, an emulsifying agent, and an antigenic substance, wherein the oil and emulsifying agent are present in the form of an oil-in-water emulsion. The adjuvant composition does not contain any polyoxypropylene-polyoxyethylene block copolymer; and the antigenic substance is not present in the internal phase of the adjuvant composition. Finally, US 20040151734 for “Vaccine and method of use” (GSK) describes a method of treating a female human subject suffering from or susceptible to one or more sexually transmitted diseases (STDs). The method comprises administering to a female subject in need thereof an effective amount of a vaccine formulation comprising one or more antigens derived from or associated with an STD-causing pathogen and an adjuvant.
There remains a need in the art for an effective RSV vaccine and methods of making and using the same. The present invention satisfies these needs.